Use of crosslinked polymers as anti-leaching agents

ABSTRACT

The invention concerns the use, in an aqueous spray mixture comprising a phytosanitary formulation, of an anti-leaching agent comprising: at least a polyhydroxyl and/or polycarboxyl polymer or copolymer; at least a crosslinking agent comprising a metal selected among columns IVA, IB and IIIB of the periodic table; said anti-leaching agent being, in the aqueous spray mixture, in the form of an aqueous solution or dispersion having a polymer or copolymer concentration such that the viscosity of the anti-leaching agent is not more than 10 times the viscosity of the aqueous solution in polymer or copolymer without crosslinking agent, having the same concentration.

This application is an application under 35 U.S.C. Section 371 ofInternational Application Number PCT/FR00/00661 filed on Mar. 17, 2000.

The present invention relates to the use, in aqueous atomizing sprayscomprising a phytosanitary formulation, of an anti-leaching agent whichcomprises at least one polyhydroxylated and/or polycarboxylated polymeror copolymer, and at least one reticulating agent comprising a metal.

The present invention relates more particularly to the sphere ofphytosanitary formulations, comprising pesticides or agents controllingthe growth of plants.

Moreover, the present invention concerns the sphere of phytosanitaryformulations intended to be applied to the plants to be treated, in theform of a solution, dispersion or emulsion in an aqueous medium. Itshould be noted that for the sake of simplicity of the preamble, in thefollowing description, reference will be made only to aqueous solutions,knowing that this term encompasses the abovementioned variants.

The phytosanitary formulations utilized in the form of an aqueoussolution are conventionally sprayed onto the plant to be treated. One ofthe main difficulties encountered with this method of use lies in thefact that it is difficult to keep the active ingredient on the plant.This is because, with the first rain or morning dew, the film depositedon the plant swells up again in the presence of water and the activeingredient is washed away with the water, which considerably reduces itsefficacy.

The present invention relates to the use of an aqueous atomizing spraycomprising a phytosanitary formulation and a special anti-leachingagent. The latter is present, while the spray is being utilized, in theform of a low-viscosity solution or dispersion. Consequently, theresultant spray can easily be pumped and atomized. Moreover, theanti-leaching agent, whilst drying on the plant being treated, forms agel, considerably limiting the leaching of the active ingredientapplied. It should be noted that, completely advantageously, the geldoes not form during the preparation or use of the spray, nor duringpreparation of the phytosanitary formulation if it contains theanti-leaching agent, but only while the spray is drying on the planttreated.

Thus, the present invention consists in the use, in an aqueous atomizingspray comprising a phytosanitary formulation, of an anti-leaching agentcomprising:

at least one polyhydroxylated and/or carboxylated polymer or copolymer,

at least one reticulating agent comprising at least one metal selectedthroughout from Columns IVA, IB and IIIB of the periodic table of theelements, said anti-leaching agent being present, in the aqueousatomizing spray, in the form of an aqueous solution or dispersion with apolymer or copolymer concentration such that the viscosity of theanti-leaching agent is less than or equal to 10 times the viscosity ofan aqueous polymer or copolymer solution free from reticulating agenthaving the same concentration.

The anti-leaching agent present in the atomizing spray, once applied tothe plant and dried, forms a reticulated film which swells only slightlyin the presence of water. The film containing the active materialtherefore retains better cohesion to the surface on which it is formed,thus considerably increasing the efficacy of the active ingredient.

The anti-leaching agent according to the invention, moreover, has othervery important advantages, such as that of avoiding losses of activeingredients during spraying. This is because the anti-leaching agentreduces the phenomena of the atomized droplets being carried away by thewind (anti-drift), and also that of their rebounding when they come intocontact with the hydrophobic surface of the plant to be treated.

It should also be noted that the anti-leaching agent may be present indifferent forms. Thus it can be present in solid form, or else in theform of a dispersion in a compound which is not a polymer or copolymersolvent, such as oils.

Moreover, the anti-leaching agents can be utilized as a phytosanitaryformulation additive. In other words, the anti-leaching agent is mixedwith the phytosanitary formulation during use of the latter; the wholeproducing the aqueous atomizing spray.

It is likewise possible to utilize phytosanitary formulations comprisingthe anti-leaching agent. In this case, the anti-leaching agent is saidto be used as a constituent of the phytosanitary formulation.

It should be noted that under the conditions described, theanti-leaching agent and optionally the phyosanitary formulationcontaining it are stable in storage and no appearance of non-manipulablegel is observed. In addition, the aqueous spray comprising thephytosanitary formulation and the anti-leaching agent is also stable.

However other advantages and characteristics of the present inventionwill become clearer on reading the description which follows.

The anti-leaching agent will first be described in detail.

As indicated above, the anti-leaching agent comprises at least onepolyhydroxylated or polycarboxylated polymer and/or copolymer.

The polymer or copolymer is preferably present in soluble form inaqueous media.

According to a first variant, the polyhydroxylated polymer or copolymeris selected throughout from polysaccharides of animal, plant orbacterial origin, cellulose derivatives or polyvinyl alcohol,polyphenolic alcohol or their derivatives, as well as glycolpolyoxalkylene derivatives.

The polysaccharides can be used in native form or chemically modified togive them an ionic, non-ionic and/or hydrophobic character differentfrom that of the native form.

The following may be cited as examples of polysaccharides, without thislist being exhaustive: alginates, galactomannanes such as guar gum,carob gum, Tara gum, cassia gum, Karaya gum, carragheenans, chitinderivatives such as chitosan, amidones, glucomannanes, dextran, gumarabic, soluble amidone and its non-ionic (cationic) derivatives. Thederivatives of these alkylated compounds are also suitable.

Of the cellulose derivatives that may be included within the presentinvention, mention may be made in particular of cellulose derivativessuch as cellulose hydroxyethers, methyl cellulose and its derivatives,hydroxypropylmethyl cellulose, hydroxybutylmethyl cellulose,carboxymethyl cellulose, ethylmethyl cellulose, ethyl cellulose,hydroxyethyl cellulose, hydroxypropyl cellulose, as well as otherhydroxyaklylated derivatives of cellulose generally.

The following can be cited as suitable derivatives of guar: compoundsresulting from an etherification and/or esterification reaction, such ashydroxyalkyl guars (with the alkyl radical comprising 2 to 4 carbonatoms, linear or branched), such as hydroxypropyl guar, hydroxybutylguar; such as carboxymethyl guar; such as carboxymethyl hydroxalkylguars (with the alkyl radical comprising 2 to 4 carbon atoms, linear orbranched). Also suitable are cationic compounds of guar, carryingquaternary amine groups. Finally, alkylated compounds of guar and of theabovementioned derivatives can be utilized in the invention.

As biogums that can be utilized in the anti-leaching agent, mention maybe made in particular of the polysaccharides obtained by fermentation bythe action of bacteria or funghi belonging, for example, to theXanthomonas, to the genus Arthrobacter, the genus Azobacter, the genusAgrobacter, the genus Alcaligenes, the genus Rhizobium, the genusSclerotium, the genus Corticium and the genus Sclerotinia.

As examples of biogums, mention can be made more particularly of xanthangum, the scleroglutanes, and the succinoglycanes.

As polyhydroxylated polymers or copolymers, and as indicated above, thefollowing are suitable: polyvinylic alcohol, the polyphenolic alcoholsor their derivatives.

The possible derivatives include the polyetherified (co)polymers, suchas those whose ether part is an alkyl radical in C₁-C₁₈, or an arylradical in C₆-C₁₆, or an alkylaryl or arylalkyl radical; the alkyl andaryl parts being defined above.

Further derivatives that may be suitable are (co)polymers carrying atleast one ionic (anionic, cationic, zwitterionic, amphoteric) radical.The following list, which is not intended to be exhaustive, includesanionic radicals: sulphonate-, sulphate-, carboxylate-, phosphate-,phosphonate-type radicals; examples of cationic radicals includequaternary ammonium-type radicals as —N(R₃)+, with R, identical ordifferent, representing a hydrogen atom, and an alkyl radical in C₁-C₆;the zwitterionic and amphoteric radicals corresponding to a combinationof the two abovementioned types of radicals.

It is noted that the polyphenolic-type (co)polymers are naturalsubstances which can, in particular, be extracted from certain plantssuch as coffee plants and tea bushes.

Another type of polyhydroxylated polymer or copolymer corresponds to thepolyolxyalkylenated derivatives of glycol, the alkylene oxide partcorresponding to ethylene oxide, propylene oxide or mixtures of these.In the case of ethylene oxide and propylene oxide being present, theirdistribution may be statistical or block. A polyoxyethylenated glycolderivative is preferably utilized.

According to a preferred variant of the invention, the polyhydroxylatedpolymer or copolymer is selected throughout from guar gum and itsnon-ionic, anionic, cationic, and amphoteric derivatives. Moreparticularly, use is made of guar, optionally alkylated, hydroxyalkylguars (with the alkyl radical comprising 2 to 4 carbon atoms, linear orbranched); carboxymethyl guar; carboxymethyl hydroxyalkyl guars (withthe alkyl radical comprising 2 to 4 carbon atoms, linear or branched)and their alkylated derivatives. In the same way, cellulose and itsderivatives such as, notably, carboxymethyl cellulose, are preferredpolyhydroxylated polymers or copolymers.

Suitable polycarboxylated polymers or copolymers are those obtainedfrom:

at least one saturated or non-saturated monomer, comprising 3 to 10carbon atoms and comprising one or more carboxylic groups present in theform of acid, or of alkaline metal salts,

optionally combined with at least one hydrocarbonated monomer carryingone or more ethylenic non-saturations; or

optionally combined with at least one alkylene-oxide-type monomer. Assaturated or non-saturated monomers comprising one or more carboxylicgroups and comprising 3 to 10 carbon atoms, mention may be made of themono- or di-acids, and their derivatives in the form of alkaline metal,alkaline-earth or ammonium salts (type N(R)₄+, with R representinghydrogen or an alkyl radical in C₁-C₄.

For example, mention may be made of acrylic acid, methacrylic acid,itaconic acid, maleic acid, maleic anhydride, and fumaric acid.

Amino-acids or their salts, e.g. aspartic acid, may likewise be suitablefor carrying out the invention.

As regards the hydrocarbonated monomer, mention can be made, withoutintending to be restrictive, of the hydrocarbonated monomers in C₂-C₁₂,which may or may not comprise an aryl radical, and also have at leastone ethylenic non-saturation. The following, amongst others, aresuitable: butadiene, isobutylene, duisobutylene, styrene, vinylstyrene,alphamethylstyrene and vinyl toluene.

In relation to the alkylene-oxide-type monomer, mention may be made ofethylene oxide, propylene oxide or mixtures of these.

The anti-leaching agent may comprise one or more of the polymers orcopolymers just described.

Moreover, the polymer or copolymer utilized in the anti-leaching agenthas, more particularly, a molecular mass by weight between 10⁴ and 5.10⁶g/mol. The molecular mass of the compound is preferably between 5.10⁵and 5.10⁶ g/mol, and according to one particular variant between 10⁶ and5.10⁶ g/mol.

These masses are measured either by chromatography by steric exclusionor by quasi-elastic diffusion of the light.

The anti-leaching agent comprises, in addition, a reticulating agentcontaining at least one metal selected throughout from Columns IVA, IBand IIIB of the periodic table of the elements (the table referred to isthat published in the supplement to the Bulletin de la Société Chimiquede France no. 1 of January 1966).

More particularly, boron is not present. The preferred metals aretitanium, zirconium, copper, and aluminium. These metals can be utilizedalone or in combination.

The reticulating agent included in the anti-leaching agent is present,more particularly, in the form of a water-soluble, water-dispersable oremulsifiable compound.

According to a first possibility, the reticulating agent is present inthe form of organic derivatives selected throughout from linear orbranched, saturated or non-saturated carboxylic or aliphatic acid saltscomprising 2 to 18 carbon atoms, and optionally comprising one or morehydroxylated groups.

For example, acetic, citric, lactic, oleic, stearic and myristoloeicacid salts are suitable.

Another variant consists in utilizing the reticulating agent in the formof aliphatic-diketone or -ketoester chelates comprising 5 to 10 carbonatoms, or comprising at least one aromatic radical.

Of the suitable compounds of this type, mention may be made of thechelates of acetyl acetone, methyl acetyl acetonate, ethyl acetylacetonate, benzoyl acetone, dibenzoyl methane, heptanoyl benzoylmethane, octanoyl benzoyl methane, isooctanoyl benzoyl methane, nonanoylbenzoyl methane, and stearoyl benzoyl methane.

According to a second possibility, the reticulating agent is utilized inthe form of mineral derivatives selected throughout from oxides,hydroxides or derivatives of these.

It should be noted that the reticulating agent can be utilized in a formthat is not, or that is only slightly, soluble in an aqueous medium. Inthis case, it will be present, when the anti-leaching agent is utilized,in the form of a dispersion, an emulsion, or a micro-emulsion.

In such a case, and in order best to promote its homogeneous dispersionwithin the aqueous atomizing spray, the reticulating agent is preferablyused in a finely divided form. More particularly the average size of theparticles is smaller than one micron and preferably less than 200 nm. Itshould be noted that the term “particles” encompasses not only thereticulating agents present in solid form, but also in liquid form, orboth.

According to one particular embodiment of the invention, thereticulating agent, if it is not, or if it is only slightly, soluble inan aqueous medium, can be utilized with an appropriate amphiphilic(dispersant, surfactant) compound, improving the homogeneousdistribution of said reticulating agent during use of the anti-leachingagent.

Highly advantageous reticulating agents suitable for the inventioninclude zirconium lactate, zirconium citrate, zirconium acetylacetonate, zirconium acetate, titanium oxide and aluminium oxide.

The weight ratio of the reticulating agent and the polymer or copolymeris more particularly between 0.005 and 2, and preferably between 0.01and 0.5.

It should be noted that the choice of constituents of the anti-leachingagent depends on the pH of the aqueous phase of the atomizing spray.Said constituents are preferably selected throughout so that they do notform a precipitate under the pH conditions to which they are subjectedduring preparation and use of said anti-leaching agent.

As indicated above, the reticulating agent, in the aqueous pulverizingspray, is present in the form of an aqueous solution or dispersionhaving a polymer or copolymer concentration such that the viscosity ofthe anti-leaching agent is less than or equal to 10 times the viscosityof an aqueous polymer or copolymer solution free from reticulating agenthaving the same concentration.

Under these conditions, and despite the presence of the two consituentsof the anti-leaching agent, the atomizing spray has a viscosity thatmakes pumping and atomizing operations simple. In addition, the spray isstable.

The spray solvent is preferably water. However, replacing the water by amixture of alcohol or polyalcohol and water would not be outside theframework of the invention. It should be noted that the quantity of thisalcohol or polyalcohol, if it is present, is such that the polymer orcopolymer is present in the form of a true solution.

Preparation of the spray can be carried out in several ways.

According to a first variant, the aqueous atomizing spray is obtained bymixing the phytosanitary formulation, which is diluted, emulsified ordispersed in an aqueous solution, with the anti-leaching agent which ispresent in solid form or in the form of a dispersion in a compound whichis not a solvent of the polymer or copolymer.

According to this first variant, the quantity of water in thephytosanitary formulation is such that the anti-leaching agent ispresent, in the aqueous atomizing spray, in the form of an aqueoussolution or dispersion having a polymer or copolymer concentration suchthat the viscosity of the anti-leaching agent is less than or equal to10 times the viscosity of an aqueous polymer or copolymer solution freefrom reticulating agent, having the same concentration.

This variant illustrates a use of the anti-leaching agent as an additive(tank-mix). The anti-leaching agent is mixed with the phytosanitaryformulation before the latter is applied to the plant to be treated.

The phytosanitary formulation which can be utilized, which will bedescribed below, can be originally in the form of a powder, granules, aconcentrated emulsion, solution or dispersion. Prior to being broughtinto contact with the anti-leaching agent, the phytosanitary formulationis diluted, emulsified, or dispersed, in an aqueous medium. Said mediumis preferably water, but the possibility of adding any other commonsolvent or dispersant is not excluded.

The quantity of water mixed with the phytosanitary formulation dependson the concentration of active ingredient required for the application,and verification of the condition mentioned above, i.e. the fact thatthe anti-leaching agent is present, in the aqueous atomizing spray, inthe form of an aqueous solution or dispersion having a (co)polymerconcentration such that the viscosity of the anti-leaching agent is lessthan or equal to 10 times the viscosity of an aqueous (co)polymersolution free from reticulating agent, having the same concentration.

A first method of carrying out this first variant consists in utilizingthe anti-leaching agent which is present in the form of a solid, moreparticularly in the form of a divided solid, such as a powder, forexample.

The anti-leaching agent can be obtained, for example, by simply mixingthe two constituents making up the anti-leaching agent.

The second method of carrying out this first variant consists inutilizing the anti-leaching agent in the form of a dispersion in acompound which is not a solvent of the polymer or copolymer.

More particularly, the compound which is not a solvent of the polymer orcopolymer is selected throughout from oils of animal or vegetableorigin, or from esters of fatty acids, or from hydrocarbonated oils. Theoils of animal origin that may be mentioned include, amongst others,sperm whale, dolphin, whale, seal, sardine, herring, dogfish, and codliver oil.

As examples of oils of vegetable origin, the following, amongst others,may be mentioned: rape-seed, sunflower, ground-nut, olive, walnut,maize, soya, linseed, hemp, grapeseed, copra, palm, cotton-seed,babassu, jojoba, sesame, castor and coriander oil. It is also possibleto utilize saturated or non-saturated fatty acid esters, comprising, forthe acid part, 6 to 40 carbon atoms, optionally carrying one or morehydroxylated groups. Examples of fatty acids that can be mentioned inparticular include oleic, myristoleic, palmitoleic, petroselenic,erucic, linoleic, linolenic and ricinoleic acid. The methyl, ethyl andpropyl esters of these acids are particularly suitable. Moreparticularly, mention may be made of the products of alcoholysis, or tobe more precise, methanolysis of the oils.

It is also possible to utilize aliphatic hydrocarbonated paraffin-typeor aromatic oils (petroleum fractions etc.).

The content of this compound which is not a solvent of the (co)polymervaries widely. However, advantageously, it represents at least 50% byweight of the anti-leaching agent ((co)polymer/reticulating agent).

According to this possibility, the polymer or copolymer can be found inthe form of solid particles.

The anti-leaching agent is advantageously obtained by simply mixing thedifferent constituents in the necessary proportions.

According to a second variant, the aqueous atomizing spray is obtainedby mixing the phytosanitary formulation with the anti-leaching agent;the latter being present in the form of an aqueous solution ordispersion having a polymer or copolymer concentration such that theviscosity of the anti-leaching viscosity is less than or equal to 10times the viscosity of an aqueous polymer or copolymer solution freefrom reticulating agent, having the same concentration.

According to this second variant, the phytosanitary formulation presentin the form of a powder, granules, or a concentrated emulsion, solutionor dispersion, is mixed with a solution or dispersion of theanti-leaching agent.

There is nothing to prevent use of a phytosanitary formulation which haspreviously been diluted, emulisified or dispersed in an aqueous medium,as soon as the concentration of active ingredient in the resultantatomizing spray is sufficient.

According to this variant, the anti-leaching agent has a water contentsuch that the polymer concentration and viscosity conditions indicatedabove are satisfactory.

This variant also illustrates a use of the anti-leaching agent as anadditive (tank-mix).

A third variant consists in preparing the atomizing sprays by diluting,dispersing or emulsifying in an aqueous medium, the phytosanitaryformulation free from water and containing the anti-leaching agent insolid form, or in the form of a dispersion in a compound which is not asolvent of the polymer or copolymer.

According to this third variant, the quantity of water is such that theanti-leaching agent, in the atomizing spray, is present in the form ofan aqeuous solution or dispersion having a polymer or copolymerconcentration such that the viscosity of the anti-leaching agent is lessthan or equal to 10 times the viscosity of an aqueous polymer orcopolymer solution free from reticulating agent, having the sameconcentration.

According to a preferred method of carrying out this variant, thephytosanitary formulation is present in a solid form containing theanti-leaching agent in solid form.

The spray is thus obtained by mixing into the phytosanitary formulationcontaining the anti-leaching agent, a sufficient quantity of an aqueousmedium, preferably water, in such a way that the above-mentioned(co)polymer concentration and viscosity conditions are verified.

This variant is representative of a use of the anti-leaching agent as aconstituent of the phytosanitary formulation.

A first method of preparation of this kind of phytosanitary formulationconsists of mixing all its constituents in the form of solids.

If necessary, the solid formulation obtained can be formed bygranulation and/or extrusion, to provide granules.

A second method of preparation consists of preparing a solution oremulsion or dispersion in an aqueous medium, of the various constituentsof the phytosanitary formulation, with the exception of one of the twoconstituents of the anti-leaching agent. This should preferably be the(co)polymer.

The resulting formulation is then dried.

The drying takes place using conventional means. However, said drying ispreferably by atomization, i.e. by atomization of the suspension in awarm atmosphere (spray-drying). This warm atmosphere is, advantageously,air.

The atomization can be carried out using any atomizer known in itself,for example an atomizing nozzle of the watering-can rose type, oranother type. “Turbine” atomizers can also be used.

A parallel-flow or counter-flow drying process can be used.

Out of the various atomizing techniques that can be utilized in thepresent procedure, reference may be made in particular to the basic workby MASTERS, entitled “SPRAY-DRYING” (second edition, 1976, George GodwinEditions, London).

It should be noted that use can also be made of the atomizing-dryingoperation using a “flash” reactor, for example of the type described inparticular in the French patent applications nos. 2,257,326, 2,419,754and 2,431,321.

By way of illustration, the gas inlet temperature during drying isbetween 150 and 250° C. Clearly, the temperature to which the activeingredient is subjected during drying remains below the degradationtemperature of the constituents of said formulation.

If Once drying is completed, the formulation obtained is then mixed withthe (co)polymer, in the conventional way.

It should be recalled that the phytosanitary formulations that can beutilized contain at least one phytosanitary active ingredient. This canbe selected throughout from pesticides (herbicides, insecticides,fungicides etc.) or plant-growth control additives (oligo-elements).

More particularly, the content of phytosanitary active ingredient issuch that the weight ratio of said active ingredient to anti-leachingagent is 0.1 to 50%.

The active ingredients included in the composition of such phytosanitaryformulations may be solid, water-soluble or water-dispersible.

Examples of suitable active ingredients include, amongst others,Ametryne, Diuron, Linuron, Chlortoluron, Isoproturon, Nicosulfuron,Metamitron, Diazinon, Aclonifen, Atrazine, Chlorothalonil, Bromoxynil,Bromoxynil heptanoate, Bromoxynil octanoate, Mancozeb, Manebe, Zineb,Phenmedipham, Propanyl, the phenoxyphenoxy series, theheteroaryloxyphenoxy series, CMPP, MCPA, 2,4-D, Simazine, the activeproducts of the imidazolinone series, the organophosphonate family,with, notably, Azinphos-ethyl, Azinphos-methyl, Alachlorine,Chlorpyriphos, Diclofop-methyl, Fenoxaprop-p-ethyl, Methoxychlorine,natural or synthetic pyrethroids, and Fenoxycarb. Aminophosphatederivatives and preferably glyphosate, sulphosate, glufosinate, andtheir organic salts (ammonium salts, which may or may not besubstituted, of which the secondary or primary amines, such asisopropylamine or dimethylamine, or diamines such as ethylene diamine,or its sulfonium salts, in particular trimethyl sulfonium) or inorganicsalts (such as alkaline metal salts such as sodium or potassium).

The active ingredient can likewise be selected throughout from mineralcompounds of the metallic oxychloride type (such as copper for example).

The present invention is likewise suitable for the preparation offormulations comprising nutrients, such as, in particular, metallicsalts such as zinc and iron, for example, and preferably manganese.These salts are used in the form of E.D.T.A.-type chelates for example,or sulphates.

The constituents of the phytosanitary formulations are those generallyused in formulations in this field.

They therefore usually comprise surfactants whose role may be tostabilize an emulsion, a suspension, or a suspension-emulsion, topromote dispersion of the active ingredient, and to promote moisteningwith other constituents of the formulation.

Said surfactants may or may not be ionic.

The quantity of surfactant utilized depends on the form of theformulation. The expert can determine this without difficulty.

Examples of anionic surfactants are given in the following list, whichis not intended to be exhaustive:

alkylsulphonic acids, arylsulphonic acids, optionally substituted by oneor more hydrocarbon groups, and of which the acid function is partiallyor wholly salified, such as alkylsulphonic acids in C₈-C₅₀, moreparticularly in C₈-C₃₀, and preferably in C₁₀-C₂₂, benzenesulphonicacids, naphthalenesulphonic acids, substituted by one to three alkylgroups in C₁-C₃₀, preferably C₄-C₁₆, and/or alkenyl groups in C₂-C₃₀,and preferably in C₄-C₁₆, mono- or diesters of alkylsulphosuccinicacids, of which the alkyl part, which may be linear or branched, mayoptionally be substituted by one or more hydroxylated and/or alcoxylatedgroups, linear or branched in C₂-C₄ (preferably ethoxylated,propoxylated, or ethopropoxylated).

ester phosphates selected throughout more particularly from thosecomprising at least one saturated, non-saturated or aromatic, linear orbranched hydrocarbonated group, comprising 8 to 40 carbon atoms,preferably 10 to 30, optionally substituted by at least one alcoxylated(ethoxylated, propoxylated, ethopropoxylated) group. In addition, theycomprise at least one ester phosphate group, mono- or diesterified insuch a way that there may be one or two free, or partially or whollysalified, acid groups. The preferred ester phosphates are of the type ofthe mono- and diesters of phosphoric acid, alcoxylated (ethoxylatedand/or propoxylated) mono-, di- or tristyrylphenol, and alcoxylated(ethoxylated and/or propoxylated) mono-, di- or trialkylphenol,optionally substituted by one to four alkyl groups; of phosphoric acidand an alcoxylated (ethoxylated, or ethopropoxylated) alcohol in C₈-C₃₀,preferably in C₈-C₂₂; phosphoric acid and a non-alcoxylated alcohol inC₈-C₂₂, preferably in C₁₀-C₂₂;

ester sulphates obtained from saturated or aromatic alcohols, optionallysubstituted by one or more alcoxylated (ethoxylated, propoxylated orethopropoxylated) groups, and for which the sulphate functions arepresent in the form of free, or partially or wholly neutralized acids.As examples, mention may be made of the ester sulphates obtained moreparticularly from saturated or non-saturated alcohols in C₈-C₂₀,optionally comprising 1 to 8 alcoxylated (ethoxylated, propoxylated orethopropoxylated) units); the ester sulphates obtained frompolyalcoxylated phenol, substituted by 1 to 3 saturated or non-saturatedhydroxycarbonated groups in C₂-C₃₀, and in which the number ofalcoxylated units is between 2 and 40; the ester sulphates obtained frompolyalcoxylated mono-, di-, or tristyrylphenol in which the number ofalcoxylated units varies from 2 to 40.

It should be noted that in cases where the compounds are in a partiallyor wholly salified form, the counter-ion may be an alkaline metal, suchas sodium or potassium, or else an ammonium ion of the formula N(R)₄+,where R, which may be identical or different, represents a hydrogen atomor an alkyl radical in C₁-C₄, optionally substituted by an oxygen atom.

Examples of non-ionic surfactants are given in the following list, whichis not exhaustive, by way of illustration:

polyalcoxylated (ethoxylated, propoxylated or ethopropoxylated) phenolssubstituted by at least one alkyl radical in C₄-C₂₀, preferably inC₄-C₁₂, or substituted by at least one alkylaryl radical, of which thealkyl part is in C₁-C₆. More particularly, the total number ofalcoxylated units is between 2 and 100. By way of example, mention maybe made of the polyalcoxylated mono-, di- or tri (phenylethyl) phenols,or the polyalcoxylated nonylphenols;

alcohols or fatty acids in C₆-C₂₂, optionally polyalcoxylated(ethoxylated, propoxylated or ethopropoxyslated). Should these bepresent, the number of alcoxylated units is between 1 and 60. The term“ethoxylated fatty acid” includes both the products obtained byethoxylation of a fatty acid by ethylene oxide and those obtained byesterification of a fatty acid by a polyethylene glycol;

polyalcoxylated (ethoxylated, propoxylated or ethopropoxylated)triglycerides of plant or animal origin. Also suitable are triglyceridesproduced from lard, tallow, ground-nut oil, butter oil, cotton grainoil, linseed oil, olive oil, palm oil, grapeseed oil, fish oil, soyaoil, castor oil, rape-seed oil, copra oil, coconut oil, and comprising atotal number of alcoxylated units between 1 and 60. The term“ethoxylated triglyceride” refers to both the products obtained byethoxylation of a triglyceride by ethylene oxide and those obtained bytrans-esterification of a triglyceride by a polyethylene glycol;

esters of polyalcoxylated (ethoxylated, propoxylated orethopropoxylated) sorbitan, more particularly esters of cyclizedsorbitol of fatty acids from C₁₀ to C₂₀ such as lauric acid, stearicacid or oleic acid, and comprising a total number of alcoxylated unitsbetween 2 and 50.

The formulations may comprise other conventional additives used in thisfield, whose properties may include, amongst others, the roles ofwetting agents, dispersants, disintegrating agents, binding agents,anti-caking agents, and/or stabilizers.

The quantity of these compounds varies widely, depending on theformation of the formulation.

Such compounds include, amongst others, salts of alkaline metals or ofalkylnaphthalene ammonium sulphonates condensed in formol; salts ofalkaline metals or of ammonium of 4,4′-dihydroxybiphenol sulphonatecondensed in formol; salts of alkaline metals or ammonium ofalkylarylphosphates or alkyarylsulphates, such as the polyoxyethylenatedand/or polyoxypropylenated mono-, di- or tristyryl phenols which may bephosphated or sulphated, neutralized or not neutralized, and mixtures ofthese. It should be noted that ammonium represents N(R)₄+, with R, whichmay be identical or different, representing hydrogen atoms orhydrocarbonated radicals in C₁-C₄.

Also suitable are alkaline-metal or ammonium salts of polymerscomprising at least one monomer selected throughout from thenon-saturated acids, diacids or anhydrides in C₃-C₅, optionally combinedwith at least one monomer selected throughout from the linear orbranched, non-saturated hydrocarbonated radicals in C₄-C₈.

More particularly, it is possible to use polymers comprising asmonomers: malic acid, malic anhydride, acrylic acid, and methacrylicacid, alone or in mixtures. Said polymers can likewise comprise at leastone monomer selected throughout from isobutylene or diisobytylene.

This polymer can be present in acid form or else in the form of analkaline metal salt or ammonium salt. The copolymer is preferably foundin the form of sodium salts. It is preferable to utilize a polymercomprising malic acid and/or malic anhydride combined with isobutyleneand/or diisobutylene. The monomers are distributed alternately in themolecule. The proportion of the acid/anhydride-type monomer in relationto the hydrocarbonated-type monomer is preferably 50/50.

It is noted that the surfactants and agents just cited are differentfrom the compounds included in the formulation as anti-leaching agent.The former do not have a molecular weight as great as that of theanti-rebound compounds utilized in the invention.

As an anti-caking agent, the following may be suitable: ammonium orsodium phosphates, sodium carbonate or bicarbonate, sodium acetate,sodium metasilicate, magnesium, zinc or calcium sulphate, magnesiumhydroxide, calcium chloride, molecular sieves, barium or calcium oxideand silica, alone or in a mixture.

Of the chemical stabilizers, mention may be made, without intending tobe restrictive, of alkaline-earth metal or transitional sulphates,sodium hexametaphosphate, calcium chloride, and boric anhydride, aloneor in a mixture.

The formulations may, if necessary, comprise one or more inert charges,such as clays, synthetic or diatomaceous silicas, calcium or magnesiumsilicates, titanium dioxide, aluminium, zinc or calcium oxide, calciumor magnesium carbonate, sodium, ammonium or calcium sulphate, and carbonblack, alone or in a mixture.

The quantity of charge, if present, can be determined without difficultyby the expert.

Preparation of the phytosanitary formulations not containing theanti-leaching agent is carried out using the conventional method in thisfield.

Thus, should the formulations be present in the form of solutions,suspensions or emulsions, the constituents of the formulation arebrought into contact, including, if necessary, the conventionaladditives assisting in the formulation, such as, for example,anti-foaming agents (e.g. silicone substances).

The operation is generally carried out without agitation at atemperature close to the ambient temperature.

Should the formulation be present in the form of a powder, a dryingstage is carried out after that of bringing the various constituents ofthe formulation into contact.

This drying takes place utilizing conventional means. A description ofthese has been given above, and will not be repeated here.

Should the phytosanitary formulation be present in solid form, thevarious constituents are generally mixed to obtain a solid or pastymixture. This mixture can then be dried.

Finally, if necessary, the solid formulation obtained can be formed bygranulation and/or extrusion, to give granules.

Concrete examples of the invention, which are not exhaustive, are givenbelow.

EXAMPLES

50 g of mixtures whose composition is summarized in the following tableare prepared:

1 4 Example (reference) 2 3 (reference) 5 6 Active 2 2 2 1 1 1ingredient (1%) (1%) (1%) (1%) (1%) (1%) (%) Guar (a) 0.1%  0.1%  0.1% 00 0 HP guar 0 0 0 0.1%  0.1%  0.1% (b) Zr lactate 0 0.044% 0.044% 00.044% 0.044% (c) CaCl₂ (d) 0 0 0.333% 0 0 0.333% (a): Guar: Meyprogat ®60 (average molar mass 500000 g/mol - marketed by Rhodia Meyhall) placedin a 1% solution in water having a pH adjusted to 5 with HCl (1M). (b):HP guar: hydroxpropyl guar Jaguar ® 105 (average molar mass 500000g/mol - marketed by Rhodia Meyhall) placed in a 1% solution in waterhaving a pH adjusted to 5 with HCl (1M). (c): Zr lactate: 29.7% solutionof zirconium lactate - Rhodoline ® RHPN (marketed by Rhodia Chimie). ThepH is adjusted to 5 by the addition of hydrochloric acid (1M). Afteradjustment of the pH, the content of dry ingredients is 15.4%. (d): Thehardness of the water is simulated by an addition of Ca²⁺ ionsequivalent to 300 ppm of CaCO₃: 0.17 g of CaCl₂ is dissolved in 9.83 gof water. This mixture is substitued for 10 g of purified water.

NB: The percentages in the table correspond to the weight of dryingredient.

Formulae 1 and 2 are as follows:

1 % 2 % Mancozeb (fungicide) 80 Bordeaux spray 77 Borresperse(Borregard) (*) 8 Borresperse (Borregard) (*) 12 Supragil MNS/90(Rhodia) (**) 2 Supragil MNS/90 (Rhodia) 5 Geropon SDS (Rhodia) (***) 2(**) Argirec B/24 (BMP clay) 8 Rhodacal DS/10 (Rhodia) 2 (***) PrussianBlue 2 Bevaloid 6352DD (Bevaloid) 2 (*) Na lignosulphate (**) condensedmethyl naphthalene (***) Na dioctyl sulphosuccinate (****) Na dodecylbezenesulphonate

The different constituents are mixed in the following order usingmagnetic agitation: water (or water+calcium ions), polymer, activeingredient then reticulating agent.

A homogeneous dispersion is obtained, whose appearance is identical tothat of a preparation of active ingredient diluted in water.

The mixtures are dried for 24 hours in aluminium cupels in a ventilatedoven at 50° C.

Part of the dry film is removed, weighed, then immersed in 300 ml ofpurified water (representing rainwater) and is left, under agitation(HEIDOLPH Promax 2020 agitating table, speed 3.5) for 30 hours.

The absorbency of the liquid in which the film is placed is measuredwith a METROHM Photometer 662 turbidimeter with a wavelength=630 nm. Theequipment is calibrated using purified water (absorbency=0).

Example 1 (reference) 2 3 4 (reference) 5 6 Absorbency 7.6 0.5 0.4 8.50.4 0.8

The abosorbency value of the samples is divided by the mass of the dryfilm placed in each receptacle (to correct variations in concentration).

What is claimed is:
 1. A method of preventing leaching of an activeagent applied to a plant with an aqueous atomizing spray comprising aphytosanitary formulation comprising said active agent, said methodcomprising the steps of: a) spraying on the plant said aqueous atomizingspray comprising said phytosanitary formulation, and an anti-leachingagent comprising: at least one polyhydroxylated or polycarboxylatedpolymer or copolymer, and at least one reticulating agent comprising atleast one metal selected from Columns IVA, IB and IIIB of the periodictable of the elements, said anti-leaching agent being present, in theaqueous atomizing spray, in the form of an aqueous solution ordispersion of the polymer or copolymer, with a polymer or copolymerconcentration such that the viscosity of the anti-leaching agent is lessthan or equal to 10 times the viscosity of an aqueous polymer orcopolymer solution free from reticulating agent, with the sameconcentration, and b) forming a gel by drying of the anti-leaching agenton the plant.
 2. A method according to the claim 1, wherein the polymeror copolymer is a polyhydroxylated polymer or copolymer and is selectedfrom the group consisting of polysaccharides of animal origin,polysaccharides of plant origin, polysaccharides of bacterial origin,polyvinyl alcohol, polyphenolic alcohols, derivatives of polyphenolicalcohols, and polyoxyalkylenated derivatives of glycol.
 3. A methodaccording to claim 1, wherein the polymer or copolymer is apolyhydroxylated polymer or copolymer and is selected from the groupconsisting of guar gum, its non-ionic derivatives, its anionicderivatives, its cationic derivatives, and its amphoteric derivatives.4. A method according to claim 1, wherein the polymer or copolymer isselected from the group consisting of guar, alkylated derivatives ofguar; hydroxyalkyl guar wherein the alkyl group comprises from 2 to 4carbon atoms, and is linear or branched, carboxymethyl guar, andcarboxymethyl hydroxyalkyl guar wherein the alkyl group comprises from 2to 4 carbon atoms, and is linear or branched.
 5. A method according toclaim 1, wherein the polymer or copolymer is a polycarboxylated polymeror copolymer, and is obtained from: at least one saturated orunsaturated monomer comprising from 3 to 10 carbon atoms, and comprisingone or more carboxylic group present in the form of an acid, or ofalkaline metal salt, optionally, at least one hydrocarbonated monomercomprising one or more ethylenic unsaturation, and optionally, at leastone monomer comprising an alkylene oxide group.
 6. A method according toclaim 1, wherein the polymer or copolymer has a molecular mass ofbetween 10⁴ and 5.10⁶ g/mol.
 7. A method according to claim 1, whereinthe reticulating agent is a water-soluble, water-dispersible oremulsifiable compound, found in the form of: organic derivativesselected from the group consisting of: linear or branched, saturated orunsaturated, aliphatic, carboxylic acid salts, comprising from 2 to 18carbon atoms, and optionally comprising one or more hydroxyl group, andaliphatic β-diketone or β-ketoester chelates, comprising from 5 to 10carbon atoms, or comprising at least one aromatic group, or mineralderivatives selected from the group consisting of oxides, hydroxides,and mixtures thereof.
 8. A method according to claim 1, wherein themetal is selected from the group consisting of zirconium, titanium,copper and aluminum.
 9. A method according to claim 1, characterized inthat a weight ratio of the reticulating agent and the polymer orcopolymer of between 0.005 and
 2. 10. A method according to claim 2,wherein the weight ratio is of between 0.01 and 0.5.
 11. A methodaccording to claim 1, wherein the aqueous atomizing spray is obtained bymixing a diluted, emulsified or dispersed, phytosanitary formulation inan aqueous medium, and an anti-leaching agent which is present in solidform, or in the form of a dispersion in a compound which is not asolvent of the polymer or copolymer, the quantity of water in thephytosanitary formulation being such that the anti-leaching agent ispresent, in the atomizing spray, in the form of an aqueous solution ordispersion having a polymer or copolymer concentration such that theviscosity of the anti-leaching agent is less than or equal to 10 timesthe viscosity of an aqueous polymer or copolymer solution free fromreticulating agent, having the same concentration.
 12. A methodaccording to claim 11, characterized in that the compound which is not asolvent of the polymer or copolymer is selected from the groupconsisting of oils of animal or vegetal origin, esters of fatty acids,and hydrocarbonated oils.
 13. A method according to claim 11, whereinthe anti-leaching agent comprises at least 50% by weight of the compoundwhich is not a solvent of the copolymer represents.
 14. A methodaccording to claim 1, wherein the aqueous atomizing spray is obtained bymixing the phytosanitary formulation with the anti-leaching agent, whichis present in the form of an aqueous solution or dispersion having apolymer or copolymer concentration such that the viscosity of theanti-leaching agent is less than or equal to 10 times the viscosity ofan aqueous polymer or copolymer solution free from reticulating agent,having the same concentration.
 15. A method according to claim 14,wherein the phytosanitary formulation is in a diluted, emulsified ordispersed form in an aqueous medium.
 16. A method according to claim 15,wherein the aqueous atomizing spray is obtained by diluting, in anaqueous medium, the phytosanitary formulation, free from water, andcontaining the anti-leaching agent in solid form or in the form of adispersion in a compound which is not a solvent of the polymer orcopolymer; the quantity of water being such that the anti-leachingagent, in the atomizing spray, is present in the form of an aqueoussolution or dispersion, having a polymer or copolymer concentration suchthat the viscosity of the anti-leaching agent is less than or equal to10 times the viscosity of an aqueous polymer or copolymer solution freefrom reticulating agent, having the same concentration.
 17. A methodaccording to claim 16, wherein the phytosanitary formulation is in solidform, comprising the anti-leaching agent in solid form.
 18. A methodaccording to claim 1, wherein the phytosanitary formulation comprises aphytosanitary active ingredient, the weight ratio of said activeingredient to anti-leaching agent being from 0.1 to 50%.